Mr Lim Soon Heng rightly points out that our heavy reliance on natural gas is not sustainable in the long term ("A floating nuclear power plant - off Singapore?"; Oct 4).

The Government should be investing in research on diversifying the future energy mix.

I agree that floating Small Modular Reactor (fSMR) technology could be considered a viable alternative energy source.

However, for the introduction of nuclear energy to be successful, there are several challenges that need to be overcome.

Singapore, with a very limited landfill, does not have the resources to deal with spent nuclear material, commonly referred to as nuclear waste.

Although it is economically possible to ship nuclear waste to a less developed country's landfill, it will be morally reprehensible to do so.

Fukushima Daiichi nuclear power plant had similar issues and stored a large quantity of spent nuclear rods on site, which contributed disastrously to the contamination of the site.

Until we find a sustainable solution to deal with waste fuel, it would be challenging to introduce nuclear power into our energy mix.

Singapore's limited territorial waters also does not provide adequate stand-off distance in a nuclear emergency incident.

While the world's best nuclear energy specialists can plan for emergency and safety measures in an fSMR, any catastrophic failure of these measures, in a world increasingly threatened by extreme weather, automatically becomes an existential threat to our country.

The benefits of a nuclear energy source in Singapore needs to be balanced with the costs of doing so, both actual and implied.

Alternatives to a floating nuclear power plant may include cross-border exportation of electricity generated in a neighbouring country.

The PUB's operation of the Linggiu Reservoir in Malaysia provides an excellent case study.

A similar concept could be considered for nuclear power.

Singapore needs to work harder at diversifying our energy mix beyond the traditional fossil fuels.

Nuclear energy generation, floating or terrestrial, could be one of the viable options if we start working on the complex challenges and create a roadmap to solve them.

Koh Teng Yong